Mobile cellular communication devices, including cellular telephones and pagers, must generally monitor and process periodic paging information when connected to the network. Mobile cellular telephones also perform neighbor cell reselection processing based upon neighbor cell signal measurements to identify the most appropriate cell, or base station, with which the cellular telephone should communicate.
Many mobile cellular telephones also operate in a minimum power consumption, sometimes referred to as sleep, mode when idling and not monitoring paging network information or performing neighbor cell signal strength measurements and reselection processing.
GSM cellular telephones generally include the foregoing idle mode functionality. Particularly, in GSM cellular telephones, it is known to receive periodic paging blocks and at the same time, between assigned slots, perform neighbor cell signal strength measurements. Thereafter, GSM cellular telephones perform neighbor cell reselection processing based upon the most recent signal strength measurements. In GSM terminals, the reselection processing does not occur until after completion of the signal strength measurements. During other idle periods, when not receiving paging blocks and performing signal strength measurements and when not performing reselection processing, GSM cellular telephones may enter sleep mode to reduce power consumption.
In many hardware designs “sleep mode” cannot be entered until all hardware functional blocks have completed processing, since all clocks are shut down in sleep mode. Sleep mode may be defined differently in other hardware designs.
WCDMA cellular telephones also generally include the foregoing idle mode functionality. Particularly, WCDMA telephones receive periodic paging indicator channel (PICH) blocks, which are much smaller than paging blocks, and at roughly the same time WCDMA telephones perform intra and inter carrier neighbor cell signal strength measurements. The PICH block in the WCDMA architectures directs the terminal to another paging channel (PCH) block only if the PICH block, and particularly the PICH bit assigned to the particular terminal, is set. Existing WCDMA cellular telephones perform neighbor cell reselection processing based upon the signal strength measurements, and like GSM reselection processing discussed above, WCDMA reselection processing does not occur until after completion of the signal strength measurements. During other idle periods, WCDMA telephones may enter sleep mode to reduce power consumption.
The various aspects, features and advantages of the present invention will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description of the Invention with the accompanying drawings described below.